Television sweep transformer



Dec. 9, 1969 w. KATUSCHENKO ET 3,483,496

TELEVI S ION SWEEP TRANSFORMER Filed Aug. 29. 1968 INVENTOR WALTERKATUSCHENKO RUDOLPH KEINATH v NEY A'ITR United States Patent 3,483,496TELEVISION SWEEP TRANSFORMER Walter Katuschenko, Syracuse, and RudolphKeinath,

Liverpool, N.Y., assignors to General Electric Corporation, acorporation of New York Filed Aug. 29, 1968, Ser. No. 756,205 Int. Cl.H01f /04, 27/28, 27/30 US. Cl. 336-84 12 Claims ABSTRACT OF THEDISCLOSURE One winding on a television transformer core serves a highvoltage filament lead. In order to shield the higll voltage filamentlead winding from a pulse winding also wound on the core, the filamentwinding is placed inside a molded insulating unit. The insulating unithas a single and double skirted portion. The double skirted portion hasan opening to provide access for the filament lead winding.

BACKGROUND OF INVENTION Field of invention This invention relates to anew and improved combination sweep transformer and high voltage powersupply assembly for television receivers having a new insulatingshielding member for the high voltage filament lead.

More particularly, the invention relates to an integral, insulatingshielding member which surrounds the core of a television receiverhorizontal sweep transformer and serves as a coil mount for the turns ofthe high voltage filament lead. The insulating shielding member isdesigned so as to facilitate quick and easy assembly of the turns of thehigh voltage filament lead thereon while providing effective and safeshielding of the high voltage filament lead from other portions of thetelevision re- In the manufacture of commercial home television receiversets, it is the practice to mount the high voltage filament lead of ahigh voltage rectifier tube employed in the high voltage power supply ofthe receiver on the core of the horizontal sweep transformer. By thisexpedient it is possible to avoid the necessity of separate, expensive,bulky and heavy core structures for both the sweep transformer and thehigh voltage power supply.

One of the problems that arises as a result of the above brieflymentioned design arrangement is that breakdown and arc-over is likely tooccur between the high voltage filament lead and some of the other partsof the receiver, such as the grounded shielding structure normallyemployed to shield the high voltage power supply as a safety measure.Due to the close proximity of the parts of the combination sweeptransformer and high voltage power supply assembly, it is difficult toavoid such breakdowns, arcovers, short circuits, and the like. One ofthe known designs for overcoming this problem employs a set of threewound paper insulating tubes to provide the necessary shielding betweenthe several parts of the assembly. Such an arrangement necessarilyinvolves relatively complex manufacturing procedures requiring properalignment of the three wound paper insulating tubes and the other partsof the combination sweep transformer and high voltage power supplyassembly. The use of such components and procedures of course increasesthe manufacturing cost of the assembly. Further, it has been determinedthat under certain conditions the shielding provided by such athree-paper tube arrangement is inade- 3,483,496 Patented Dec. 9, 1969"ice quate and that breakdown or arc-over will occur. In other knownarrangements Where the shielding provided is adequate to preventbreakdown and arc-over, the manufacturing techniques and requirementsfor assembly are so demanding that only highly skilled personnel orexpensive machinery can accomplish assemblage of the components. Toovercome these problems, the present invention was devised.

SUMMARY OF INVENTION It is therefore a primary object of the presentinvention to provide a new and improved combination television sweeptransformer and high voltage power supply assembly for use in commercialhome television receiving sets which employs a new and improvedinsulating shielding member for the high voltage filament lead, isreadily assembled, and provides safe, effective shielding againstbreakdown and arc-over during operation.

Another object of the invention is to provide a new and improvedinsulating shielding member for use in combination television sweeptransformer and high voltage power supply assemblies which is ofunitary, molded, flexible construction, relatively inexpensive tomanufacture, easy to assemble with other elements into a desiredassembled relationship, and which provides effective and safe shieldingof the high voltage filament lead.

In practicing the invention, a combination television sweep transformerand high voltage power supply assembly is provided which includes a coremember and a high voltage filament lead having at least one turn woundaround the core member and supported on an insulating unit surroundingthe core member. The insulating unit comprises an integral, insulatingbody member having a single skirted portion comprised by a single layerof insulating material surrounding the core member and adapted to have asweep transformer winding wound thereon. The integral insulating bodymember further includes a double skirted portion comprised by a pair ofspacedapart inner and outer insulating layers joined together by aflange portion with the single skirted portion being joined to thedouble skirted portion at the flange portion, and being in substantialaxial alignment with the inner insulating layer of the double skirtedportion. The outer insulating layer of the double skirted portion has arelatively narrow, axially extending access opening formed therein toprovide ready access for the turns of the high voltage filament lead tothe space between the inner and outer insulating layers.

The insulating unit preferably is formed of an integral, molded unit ofthermoplastic material, such as polypropylene, with at least the outerinsulating layer being flexible so as to facilitate winding of the turnsof the high voltage filament lead in the space provided between theouter and inner layers of the double skirted portion. The end of thedouble skirted portion of the integral, molded insulating unit oppositethe flange portion thereof is openended and extends beyond the turns ofthe high voltage filament lead a substantial distance so as to shieldeffectively the turns of the high voltage filament lead. The inintegral,molded insulating unit preferably is generally cylindrically-shaped andincludes an annular reinforcing ridge portion adjacent the flangeportion at the juncture of the single skirted portion with the doubleskirted portion.

BRIEF DESCRIPTION OF DRAWINGS Other objects, features and many of theattendant advantages of this invention will be appreciated more readilyas the same becomes better understood by reference to the followingdetailed description, when considered in connection with theaccompanying drawings, wherein like parts in each of the several figuresare identified by the same reference character, and wherein:

FIGURE 1 is a side view of a prior art combination sweep transformer andhigh voltage power supply assembly which employs three wound paper tubesto provide shielding between the high voltage filament lead and otherportions of the assembly;

FIGURE 2 is a partially broken away side View of a combination sweeptransformer and high voltage power supply assembly constructed inaccordance with the invention, and employing a new and improvedintegral, molded insulating shielding member constructed in accordancewith the invention;

FIGURE 3 is an end view of the new and improved insulating shieldingmember constructed in accordance with the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT FIGURE 1 is a side view ofa prior art combination sweep transformer and high voltage power supplyassembly which employs three wound paper tubing insulating members shownat 11, 12 and 13 with the paper tubing or paper coil form 13 surroundinga cylindrical-shaped core member 14. The cylindrically-shaped coremember 14 may comprise the C-core structure of a horizontal sweeptransformer used in a commercial home television receiving set. For thispurpose, a pulse winding shown at 15 is wound around the paper coil form13. As is now well known in the art, the core member 14 also is employedas the core of a high voltage transformer comprised in part by a highvoltage filament lead shown at 16 and also wound around the paper coilform 13 at a point spaced from the pulse winding 15. In order toproperly shield and isolate the high voltage filament lead 16, the woundpaper tubing members 11 and 12 are disposed on opposite sides of lead16. In order to maintain or secure the turns of the high voltagefilament lead 16 in place on the structure thus assembled, a band ofelastic neoprene tubing shown at 17 is secured over the ends of the lead16 in the manner shown in FIGURE 1.

From the above description, it will be appreciated that during assemblyof the structure shown in FIGURE 1, it is necessary to first slide thepaper coil form 13 into position, then in the proper order insert thepaper tubing 11 and 12, separately wind the pulse winding 15 and thehigh voltage filament lead 16 after first threading the leads throughthe neoprene tubing 17. All of these requirements unduly complicate theconstruction of the assembly and consequently increase its cost, andrequire somewhat skilled labor. In addition, during operation, undercertain kinds of atmospheric conditions, the possibility of breakdown orarc-over between the high voltage filament lead 16 and a groundedshielding structure normally enclosing the assembly shown in FIGURE 1,can occur. To overcome all of these problems, the assembly shown in FIG-URE 2 was devised.

FIGURE 2 is a partially broken away side view of a new and improvedcombination television sweep transformer and high voltage power supplyassembly constructed in accordance with the invention. The assemblyshown in FIGURE 2 is comprised by a core member 14 and high voltagefilament lead 16 having at least one turn but preferably a multiplicityof turns wound around the core member and supported on a single,integral, insulating shielding unit which surrounds the core member 14and serves as a coil mount for both the high voltage filament lead 16and the turns of a sweep transformer winding shown at 15. The insulatingunit is comprised by an integral, molded insulating body member ofpolypropylene which has a single skirted portion 21 surrounding the coremember 14 and having the sweep transformer winding 15 wound thereon. Theintegral insulating unit further includes a double skirted portion 22comprised by a spacedapart inner insulating layer 23 and outerinsulating layer 24 which are joined together by a flange portion 25.The single skirted portion 21 is joined to and integral with the doubleskirted portion 22 at the flange portion 25 and is in substantial axialalignment with the inner insulating layer 23. The outer insulating layer24 has a relatively narrow, axially extending access opening 26 formedtherein to provide ready access for the turns of the high voltagefilament lead 16 into the space between the inner and outer insulatinglayers 23 and 24. As stated previously, the integral, insulating unit isan integral molded unit of plastic material such as polypropylene withat least the outer insulating layer 24 being suificiently thin and fabricated in a manner such that it is flexible so as to facilitate windingof the turns of the high voltage filament lead 16 in the space providedbetween the inner and outer layers 23 and 24, respectively.

As is best shown in FIGURE 2, the end of the double skirted portion 22of the integral insulating unit opposite the flange portion 25 thereof,is open-ended and extends beyond the turns of the high voltage filamentlead 16 a considerable distance so as to substantially surround theturns of the high voltage filament lead and to shield them eflfectively.In order to retain the turns of the high voltage filament lead 16 in thespace between the inner and outer insulating layers 23 and 24,respectively, the insulating unit further includes at least one holdingtab shown at 27 in FIGURE 3. The holding tab 27 is formed on the openend of the double skirted portion 22 and extends inwardly into the spacebetween the inner and outer layers 23 and 24, respectively, forretaining the turns of the high voltage filament lead in the space.

As is best seen in both FIGURES 2 and 3 considered together, therelatively narrow access opening 26 in the outer insulating layer 24extends axially and is formed in an offset housing part 28 that extendsthe full length of the double skirted portion 22 with the access opening26 being formed with a generally T-shaped configuration. This T -shapedconfiguration for the access opening is arranged so that the enlargedcrossed head of the T-shaped opening is located adjacent the flangeportion 25 in a manner such that the high voltage filament lead 16 maybe readily inserted and slipped through the relatively narrow throatportion of opening 26, wound into place around the inner insulatinglayer 23, held there by tab 27, and restrained from unwinding by thesides of the enlarged T- shaped head of the opening which also allowsthe separate ends of the high voltage filament lead 16 to extend indifferent directions, Thus, it will be appreciated that the shape of theopening 26 greatly facilitates assembly of the turns of the high voltagefilament lead 16 on the shielding insulating body member and yet theconstruction of the body member is such that substantial shielding ofthe turns of the high voltage filament lead, is provided.

From a consideration of FIGURES 2 and 3 of the drawings, it will beappreciated that the specific embodiment of the invention disclosed isgenerally cylindrical in shape and preferably includes an annularreinforcing ridge portion 29 which is disposed adjacent the flangeportion 25 at the juncture of the single skirted portion 21 with thedouble skirted portion 22. The provision of such an annular reinforcingridge portion provides additional strength to the unit which enables itto physically withstand the rigors of the winding operation to which itis subjected, and further improves the electrical shieldingcharacteristics between the turns of the high voltage filament lead 16and the turns of the sweep transformer 15.

From the foregoing description, it will be appreciated that theinvention makes available a new and improved combination sweeptransformer and high voltage power supply assembly having a new singlepolypropylene insulating shielding unit which can be easily injectionmolded and whose flexible characteristics (at least on the doubleskirted portion thereof that supports the high voltage filament lead)allows easy insertion during manufacturing and provides a fixed leadlocation. During operation of such an assembly, the high voltagefilament lead normally will be subjetced to voltages in the neighborhoodof kilovolts; but in the event of a failure somewhere in the powersupply circuit, this voltage can go up to about 35 kilovolts. Even underthese conditions, as well as adverse environmental conditions such ashigh moisture content (high relative humidity) of the environment inwhich the assembly is used, the high voltage filament lead iseffectively and safely shielded so that breakdown and arc-over from the.high voltage filament winding to the sweep transformer windings or to agrounded shield structure, is avoided.

It will be appreciated, therefore, that the invention provides a new andimproved combination television sweep transformer and high voltage powersupply assembly for use in commercial home television receiving sets andwhich employs an improved insulating shielding member for the highvoltage filament lead, is readily assembled, and provides safe andeffective shielding against breakdown and arc-over during operation. Thenew and improved insulating shielding member is of unitary, molded,flexible construction, relatively inexpensive to manufacture, easy toassemble with other elements into a desired assembled structure, andprovides effective and safe shielding of the high voltage filament leadwhich it supports.

Having described one embodiment of a new and improved combinationtelevision sweep transformer and high voltage power supply assembly andinsulating shielding member therefor constructed in accordance. with theinvention, it is believed obvious that other modifications andvariations of the invention are possible in the light of the aboveteachings. It is therefore to be understood that changes may be made inthe particular embodiment of the invention described which are withinthe full intended scope of the. invention as defined by the appendedclaims.

What is claimed is:

1. A combination television sweep transformer and high voltage powersupply assembly including a core member and a high voltage filament leadhaving at least one turn wound around the core member and supported onan insulating unit surrounding the core member, the insulating unitcomprising an integral insulating body member having a single skirtedportion comprised by a single layer of insulating material surroundingthe core member and adapted to have a sweep transformer Winding woundthereon, and a double skirted portion comprised by a pair ofspaced-apart inner and outer insulating layers joined to gether by aflange portion with the single skirted portion being joined to thedouble skirted portion at the flange portion and being in substantialaxial alignment with the inner insulating layer of the double skirtedportion, the outer insulating layer of the double skirted portion havinga relatively narrow access opening formed therein to provide access forthe turns of the high voltage filament lead to the space between theinner and outer insulating layers.

2. A television sweep transformer and high voltage power supply assemblyaccording to claim 1 wherein the insulating unit is an integral moldedunit of thermoplastic material with at least the outer insulating layerbeing flexible so as to facilitate winding of the turns of the highvoltage filament lead in the space provided between the outer and innerlayers of the double skirted portion.

3. A television sweep transformer and high voltage power supply assemblyaccording to claim 1 wherein the end of the double skirted portion ofthe insulating unit opposite the flange portion thereof is open-endedand extends beyond the turns of the high voltage filament lead asubstantial distance so as to shield effectively the turns of the highvoltage filament lead, and wherein the insulating unit further includesat least one holding tab formed on the open end of the double skirtedportion thereof and extending inwardly into the space between the innerand outer layers for retaining the turns of the high voltage filamentlead in the space.

4. A television sweep transformer and high voltage power supply assemblyaccording to claim 1 wherein the relatively narrow access opening in theouter insulating layer of the insulating unit double skirted portionextends axially and is formed in an offset housing part of the doubleskirted portion with a generally T-shape and with the crossed head ofthe T-shape opening located adjacent the flange portion whereby assemblyof the turns of the high voltage filament lead in the space between theinner and outer insulating layers of the double skirted portion isgreatly facilitated.

5. A television sweep transformer and high voltage power supply assemblyaccording to claim 1 wherein the insulating unit is generallycylindrically-shaped and includes an annular reinforcing ridge portionadjacent the flange portion at the juncture of the single skirtedportion with the double skirted portion.

6. A television sweep transformer and high voltage power supply assemblyaccording to claim 2 wherein the end of the double skirted portion ofthe insulating unit opposite the flange portion thereof is open-endedand extends beyond the turns of the high voltage filament lead asubstantial distance so as to shield effectively the turns of the highvoltage filament lead, the insulating unit further includes at least oneholding tab formed on the open end of the double skirted portion thereofand extending inwardly into the space between the inner and outer layersfor retaining the turns of the high voltage filament lead in the space,the relatively narrow access opening in the outer insulating layer ofthe insulating unit double skirted portion extends axially and is formedin an offset housing part of the double skirted portion with a generallyT-shape and with the crossed head of the T- shape opening locatedadjacent the flange portion whereby assembly of the turns of the highvoltage filament lead in the space between the inner and outerinsulating layers of the double skirted portion is greatly facilitated,and the insulating unit is generally cylindrically-shaped and includesan annular reinforcing ridge portion adjacent the flange portion at thejuncture of the single skirted portion with the double skirted portion.

7. An insulating unit for a combination television sweep transformer andhigh voltage power supply assembly comprising an integral insulatingbody member having a single skirted portion formed by a single layer ofinsulating material and adapted to surround a television sweeptransformer core member and to have a sweep transformer winding woundthereon, and a double skirted portion comprised by a pair ofspaced-apart inner and outer insulating layers joined together by aflange portion with the single skirted portion being joined to thedouble skirted portion at the flange portion and being in substantialaxial alignment with the inner insulating layer of the double skirtedportion, the outer insulating layer of the double skirted portion havinga relatively narrow access opening formed therein to provide access forthe turns of a high voltage filament lead to the space between the innerand outer insulating layers.

8. An insulating unit according to claim 7 wherein the insulating unitis an integral molded unit of polypropylene with at least the outerinsulating layer being flexible so as to facilitate winding of the turnsof a high voltage filament lead in the space provided between the outerand inner layers of the double skirted portion.

9. An insulating unit according to claim 7 wherein the end of the doubleskirted portion of the insulating unit opposite the flange portionthereof is open-ended and extends beyond the turns of a high voltagefilament lead wound therein a substantial distance so as to shieldeffectively the turns of the high vlotage filament lead, and includes atleast one holding tab formed on the open end thereof and extendinginwardly into the space between the inner and outer layers for retainingthe turns of the high voltage filament lead in the space.

10. An insulating unit according to claim 7 wherein the relativelynarrow access opening in the outer insulating layer of the insulatingunit double skirted portion extends axially and is formed in an offsethousing part of the double skirted portion with a generally T-shape andwith the crossed head of the T-shape opening located adjacent the flangeportion whereby assembly of the turns of a high voltage filament lead inthe space between the inner and outer insulating layers of the doubleskirted portion is greatly facilitated.

11. An insulating unit according to claim 7 wherein the insulating unitis generally cylindricallyshaped and includes an annular reinforcingridge portion adjacent the flange portion at the juncture of the singleskirted portion with the double skirted portion.

12. An insulating unit according to claim 7 wherein the insulating unitis an integral molded unit of polypropylene with at least the outerinsulating layer being flexible so as to facilitate winding of the turnsof a high voltage filament lead in the space provided between the outerand inner layers of the double skirted portion, the end of the doubleskirted portion of the insulating unit opposite the flange portionthereof is open-ended and extends beyond the turns of a high voltagefilament lead wound therein a substantial distance so as to elfectivelyshield the turns of the high voltage filament lead, at least one holdingtab is formed on the open end of the double skirted portion and extendsinwardly into the space between the inner and outer layers for retainingthe turns of the high voltage filament lead in the space, the relativelynarrow access opening in the outer insulating layer of the insulatingunit double skirted portion extends axially and is formed in an offsethousing part of the double shielded portion with a generally T-shape andwith the crossed head of the T-shape opening located adjacent the flangeportion whereby assembly of the turns of a high voltage filament lead inthe space between the inner and outer insulating layers of the doubleskirted portion is greatly facilitated, and the insulating unit isgenerally cylindrically-shaped and includes an annular reinforcing ridgeportion adjacent the flange portion at the juncture of the singleskirted portion with the double skirted portion.

References Cited UNITED STATES PATENTS 1,955,130 4/1934 Israel 336-208 X2,910,529 10/1959 Splitt 336180 X E. A. GOLDBERG, Primary Examiner U.S.Cl. X.R.

